Miller has confirmed that the vulnerability Apple patched was the one he used last month to earn a $10,000 prize. “That must be it,” he said. “I haven’t given them any other bugs.”

In fact, Miller refused to divulge additional bugs he’d found in Apple’s operating system during the conference, instead giving a presentation on how he used “dumb fuzzing” techniques to uncover more than 20 exploitable vulnerabilities in Adobe, Apple and Microsoft software. During the presentation, Miller argued that security is a “broken record,” and said that it was more effective in the long run to simply show the companies how to replicate his work.

“What I can do is tell them how to find these bugs, and do what I did. That might get them to do more fuzzing,” Miller said in a March interview. That, he maintained, would result in more secure software.

Apple slashed the time it took to patch Miller’s Pwn2Own bug by more than half compared to last year, when he also hacked Mac OS X at the contest. In 2009, Apple took 55 days to fix the flaw ; this year, it needed just 21 days.

“That’s pretty fast,” said Miller earlier this week. “It’s not like there’s a rush. I didn’t tell anyone about the bug.”

Pwn2Own rules require researchers to keep quiet until their vulnerabilities are patched. 3Com Corp.’s TippingPoint division, which sponsors the contest, purchases all rights to the vulnerability and exploit research, which it turns over to the vendor. TippingPoint also stays mum until a patch is released.

3Com was recently acquired by Palo Alto, Calif.-based Hewlett-Packard Development Company L.P.

“If they had taken four months or more, it wouldn’t have mattered,” Miller said.

According to Apple, the vulnerability Miller exploited was in ATS (Apple Type Services), a font renderer included with Mac OS X. “Viewing or downloading a document containing a maliciously crafted embedded font may lead to arbitrary code execution,” Apple said in the advisory accompanying the one-patch update. “An unchecked index issue exists in Apple Type Services’ handling of embedded fonts.”

Apple wasn’t the first to patch a Pwn2Own bug. Mozilla, which watched its Firefox browser fall on the same day Miller hacked Safari, issued an update that fixed the exploited flaw on April 1, just eight days after the contest. Mozilla also increased its patch speed this year, beating last year’s time by two days.

Microsoft Corp. has not released a patch for Internet Explorer 8 (IE8) , the third desktop browser hacked by Pwn2Own researchers on March 24. Apple must also update its iPhone software to plug a hole used by a pair of hackers to break into the iconic smartphone at Pwn2Own. Vincenzo Iozzo and Ralf-Philipp Weinmann won $15,000 for their efforts.

The security update, which applies to both Snow Leopard and Leopard, or Mac OS X 10.5, can be downloaded from the Apple site or installed using Mac OS X’s integrated update service. The updates range in size from 6.5MB for Snow Leopard to 218MB for Leopard and 379MB for Leopard Server.